The Igls criteria were developed to provide a consensus definition for outcomes of β-cell replacement therapy in the treatment of diabetes during a January 2017 workshop sponsored by the International Pancreas & Islet Transplant Association (IPITA) and the European Pancreas & Islet Transplant Association (EPITA). In July 2019, a symposium at the 17 th IPITA World Congress was held to examine the Igls criteria after two years in clinical practice, including validation against continuous glucose monitoring (CGM)-derived glucose targets, and to propose future refinements that would allow for comparison of outcomes with artificial pancreas system approaches.